CN211086427U

CN211086427U - Test pencil

Info

Publication number: CN211086427U
Application number: CN201921293271.5U
Authority: CN
Inventors: 杨晓峰; 李发友
Original assignee: Dongguan Huabo Precision Measuring Instrument Technology Co ltd
Current assignee: Dongguan Huabo Precision Measuring Instrument Technology Co ltd
Priority date: 2019-08-08
Filing date: 2019-08-08
Publication date: 2020-07-24
Anticipated expiration: 2029-08-08

Abstract

The utility model discloses a test pencil, including form of a stroke or a combination of strokes shell, circuit board, microcontroller, voltage measurement mode switching unit, induction element, display element, be equipped with sensing signal input point, non-contact voltage signal acquisition module, contact voltage signal acquisition module and change over switch on the circuit board, the circuit board is located form of a stroke or a combination of strokes shell, induction element locates the front end of form of a stroke or a combination of strokes shell and contacts with sensing signal input point; the microcontroller is arranged on the circuit board, and the display unit is arranged on the pen-shaped shell and connected with the microcontroller; the voltage measurement mode switching unit is disposed on the pen-shaped housing and operates the switch to switch between the noncontact voltage measurement mode and the contact voltage measurement mode. The utility model discloses a test pencil has non-contact voltage measurement and contact voltage measurement function concurrently.

Description

Test pencil

Technical Field

The utility model relates to an electrical measurement field especially relates to a test pencil.

Background

The non-contact test pencil and the contact test pencil sold in the market at present are two different door-type test pencils. The non-contact test pencil is because direct and electric isolated, the human body can not electrocute, it is relatively safer, but can only survey approximate alternating voltage, and the contact test pencil adopts contact voltage, reduce the electric current through the bulk resistor, realize the measurement of voltage as ground conductor with the human body, the danger of human direct electric shock will appear like this, consequently some electricians under the general condition will buy these two kinds of test pencils, judge electric wire or socket electrification power with the non-contact test pencil earlier, then go to measure the voltage size of electrified body with the contact test pencil according to the condition, can increase the purchase cost like this, if forget to carry one of them pen, all can not conveniently carry out voltage measurement, it is not very convenient to use.

SUMMERY OF THE UTILITY MODEL

A primary object of the present invention is to provide a test pencil with non-contact voltage and voltage measurement and contact voltage and voltage measurement functions.

In order to achieve the above object, the present invention provides a test pencil, which comprises a pencil-shaped housing, a circuit board, a microcontroller, a voltage measurement mode switching unit, an induction unit, and a display unit, wherein the circuit board is provided with an induction signal input point, a non-contact voltage signal acquisition module, a contact voltage signal acquisition module, and a switch, the circuit board is disposed in the pencil-shaped housing, and the induction unit is disposed at the front end of the pencil-shaped housing and contacts with the induction signal input point; the microcontroller is mounted on the circuit board, and the display unit is mounted on the pen-shaped housing and connected with the microcontroller;

the voltage measurement mode switching unit is arranged on the pen-shaped shell and used for operating the switch so as to switch between a non-contact voltage measurement mode and a contact voltage measurement mode;

the non-contact voltage signal acquisition module is used for acquiring the voltage to be detected in a non-contact mode through the induction unit in a non-contact voltage measurement mode and outputting the acquired signal to the microcontroller;

the contact voltage signal acquisition module is used for acquiring the voltage to be detected in a contact mode through the induction unit in a contact voltage measurement mode and outputting the acquired signal to the microcontroller;

the microcontroller is used for processing signals input by the non-contact voltage signal acquisition module/the contact voltage signal acquisition module to acquire the magnitude of the voltage to be detected and sending a corresponding first control signal to the display unit according to the acquired magnitude of the voltage to be detected;

the display unit is used for displaying a voltage intensity identification corresponding to the acquired voltage to be detected according to the first control signal so that a user can know the strength of the detection voltage of the current test pencil.

Preferably, the pen-shaped housing includes a hollow pen body and a cap disposed at a front end of the pen body, the circuit board is disposed in the pen body of the pen-shaped housing, and the sensing unit is disposed on the cap of the pen-shaped housing and in contact with the sensing signal input point.

Preferably, the change-over switch is a tact switch, and the tact switch is turned on and released, that is, turned off, by pressing the tact switch through the voltage measurement mode switching unit.

Preferably, the voltage measurement mode switching unit includes a sliding rod and a pressing plate, a first through hole is formed in the pen-shaped housing corresponding to an outer end of the sliding rod, a second through hole is formed in the pressing plate corresponding to an inner end of the sliding rod, the outer end of the sliding rod penetrates through the first through hole to extend out of the pen-shaped housing, the inner end of the sliding rod penetrates through the second through hole to press the tact switch, and the sliding rod is mounted on the pen-shaped housing through the pressing plate and can slide in the first through hole and the second through hole.

Preferably, the first through hole is formed in the front end plate of the cap, the sliding rod is mounted on the inner side of the front end plate of the cap through the pressing piece, the outer end of the sliding rod extends out of the front end plate of the cap, the test pencil further comprises a pencil cap for covering the cap, the pencil cap is used for abutting against the outer end of the sliding rod when covering the front end of the cap, the inner end of the sliding rod moves towards the tact switch to press the tact switch, the tact switch is switched on after being pressed and switched to a non-contact voltage measurement mode, when the pencil cap is taken down from the cap, acting force on the outer end of the sliding rod is removed, and the tact switch is restored to an off state under the action of self elasticity and switched to a contact voltage measurement mode.

Preferably, a convex ring is formed in the middle of the sliding rod, and the convex ring is clamped between a front end plate of the cover head and the pressing sheet to limit the sliding stroke of the sliding rod.

Preferably, the induction unit includes screw blade seat and screwdriver pole, the screw blade seat is installed on the caping, the screwdriver pole is installed on the screw blade seat and outwards stretch out the caping, cap for brush lid is in when the caping, still be used for with the screw blade pole shroud is in the cap for brush, screw blade seat and screwdriver pole be used for with induction signal input point conductive connection.

Preferably, the induction unit still includes the response piece of platykurtic, the outer end of cap for brush is provided with the portion of acceping of platykurtic, the response piece is located in the portion of acceping of cap for brush, the response piece is used for cap for brush shroud be in when overhead with screwdriver pole carries out the conductive connection, be connected with compression spring on the response piece, compression spring is used for cap for brush shroud be in when overhead with the response piece with screwdriver pole conductive connection.

Preferably, the screwdriver rod is detachably mounted on the screwdriver seat, a screwdriver head is formed at one end of the screwdriver rod or screwdriver heads are formed at two ends of the screwdriver rod, or the screwdriver rod is fixed on the screwdriver seat in an undetachable manner.

Preferably, the head shape of the screwdriver head is a straight line, a cross, a Chinese character 'mi', a star shape, a square head, a hexagonal head or a Y shape.

Preferably, the circuit board is provided with a contact piece contacting with the induction signal input point, one side of the contact piece facing the screwdriver seat is provided with a contact spring, and the contact spring is used for being in conductive connection with the screwdriver seat of the induction unit.

Preferably, a blind hole is formed in one side, facing the contact spring, of the screwdriver seat, a magnetic suction block is arranged in the blind hole, and the contact spring is electrically connected with the screwdriver seat through the magnetic suction block.

Preferably, the circuit board is further provided with a key module, the key module comprises a power key and a sensitivity key, the power key is used for controlling the test pencil to be turned on and off, and the sensitivity key is used for switching the sensitivity range of the test pencil.

Preferably, still be equipped with the light module on the circuit board, the light module is including the light that is used for the illumination, the light stretches into to the caping in, the front end of caping corresponds the light is equipped with the light-emitting window, sensitivity key SKEY still is used for opening and closes the light.

Preferably, still be equipped with function pilot lamp module on the circuit board, function pilot lamp module is including the power indicator that instructs the power to open, and power indicator is used for lighting when the power is opened.

Preferably, the display unit displays the voltage intensity indication by using an L CD display screen, a nixie tube or a L ED lamp.

Preferably, the voltage intensity marks are analog bars, and the display unit displays the analog bars with the number corresponding to the size of the acquired voltage to be detected according to the first control signal; or the voltage intensity is identified as a voltage value.

Preferably, the display unit lights L ED lamps and/or lights L ED lamps of different colors according to the first control signal to represent the voltage intensity indication.

Preferably, the display unit includes an L CD display screen, the circuit board is further provided with a two-color backlight module, and the two-color backlight module includes two light emitting diodes emitting different colors, respectively, for lighting two different colors of backlight for the L CD display screen.

Preferably, the display unit is used for displaying corresponding characters and/or symbols in the non-contact voltage measurement mode, displaying corresponding characters and/or symbols in the contact voltage measurement mode, and/or displaying an undervoltage battery symbol in the undervoltage battery mode.

Preferably, still be equipped with buzzing alarm module on the circuit board, buzzing alarm module includes bee calling organ, microcontroller still is used for controlling according to the size of the voltage that detects that acquires the bee calling organ sends the frequency sound corresponding with the voltage that detects that acquires, buzzing alarm module further includes the signal lamp, microcontroller still is used for controlling the signal lamp lights the luminance corresponding with the voltage that detects that acquires, or control the signal lamp sends the scintillation frequency corresponding with the voltage that detects that acquires.

Preferably, the sensitivity range of the non-contact voltage measurement mode comprises a high sensitivity range of 12V-1000V and a low sensitivity range of 48V-1000V.

Preferably, the sensitivity range of the non-contact voltage measurement mode comprises a 12V-1000V high-sensitivity range and a 48V-1000V low-sensitivity range, when the measurement is carried out under the 12V-1000V high-sensitivity range, the 12V-1000V high-sensitivity measurement is divided into a plurality of sections, different colors of backlight of an L CD display screen are lightened through a two-color backlight module, different levels of prompt sounds are emitted through a buzzer BUZ, and/or different numbers of simulation bars are displayed through a L CD display screen to represent the voltage section where the detection voltage is located;

when measuring under the low-sensitivity range of 48V-1000V, dividing the low-sensitivity range of 48V-1000V into a plurality of sections, lighting different colors of backlight of an L CD display screen through a two-color backlight module, giving out different levels of prompting sound through a buzzer BUZ, and/or displaying different numbers of simulation bars through a L CD display screen to represent the voltage section where the detection voltage is located;

preferably, when the contact voltage measurement mode is used for measurement, the voltage detection range is 12-250V, the voltage detection range is divided into a plurality of sections, different color backlights of an L CD display screen are lightened through a two-color backlight module, and/or different numerical values are displayed through a L CD display screen to represent the voltage section where the detection voltage is located.

Preferably, still be equipped with the light module on the circuit board, the light module is including the light that is used for the illumination, the light stretches into to the caping in, the front end of caping corresponds the light is equipped with the light-emitting window.

Preferably, the change-over switch is a toggle switch, the voltage measurement mode change-over unit includes a toggle key disposed on the pen body, and the toggle switch is operated by the toggle key to switch between the non-contact voltage measurement mode and the contact voltage measurement mode.

Preferably, the circuit board is further provided with a phase sequence signal acquisition module and a key module, the key module comprises a function switching key FUNC, and the function switching key FUNC is used for switching between a non-contact voltage measurement mode and a non-contact phase sequence measurement mode.

Preferably, the circuit board is further provided with a function indicator light module, the function indicator light module includes a phase sequence indicator light for indicating a non-contact phase sequence measurement mode, and the phase sequence indicator light is turned on when the non-contact phase sequence measurement mode is switched.

Preferably, the phase sequence signal acquisition module is configured to acquire a phase sequence of the three-phase line to be detected in a non-contact manner through the sensing unit in a non-contact phase sequence measurement mode, and output an acquired signal to the microcontroller;

the microcontroller is also used for processing the signals input by the phase sequence signal acquisition module to obtain a phase sequence detection result, and sending corresponding second control signals to the display unit according to the phase sequence detection result;

and the display unit is used for correspondingly displaying the phase sequence detection result according to the second control signal.

Preferably, the display unit is further used for displaying corresponding characters and/or symbols in the non-contact phase sequence measurement mode; and/or

The display unit is also used for displaying a right-handed sign in the measurement result as a positive phase sequence and displaying a left-handed sign in the measurement result as a negative phase sequence.

Preferably, the display unit includes an L CD display screen, the circuit board is further provided with a bi-color backlight module, the bi-color backlight module includes two light emitting diodes emitting different colors, respectively, and the bi-color backlight module is configured to illuminate the different color backlights of the L CD display screen to represent a positive phase sequence and a negative phase sequence when displaying a phase sequence measurement result.

The utility model provides a pair of test pencil through setting up non-contact voltage signal acquisition module, contact voltage signal acquisition module and change over switch, only needs to carry a test pencil, can enough realize the non-contact measurement of voltage, can realize the contact measurement of voltage again, and it is more convenient to carry and use. When measuring the voltage, non-contact measurement can be selected, and contact measurement is adopted when the voltage is determined to be within the safety range, so that the personal safety of a user can be guaranteed, and higher measurement accuracy is achieved.

Drawings

Fig. 1 is a schematic structural diagram of a preferred embodiment of the test pencil of the present invention.

Fig. 2 is an exploded view of the test pencil of fig. 1.

Fig. 3 is an exploded view of the test pencil of fig. 1 from another perspective.

Fig. 4 is a top view of the test pencil of fig. 1.

Fig. 5 is a cross-sectional view of the test pencil of fig. 1 taken along line a-a of fig. 4.

Fig. 6 is a cross-sectional view of the test pencil of fig. 1 taken along line B-B of fig. 4.

Fig. 7 is a schematic block diagram of the circuit of a preferred embodiment of the test pencil of the present invention.

Fig. 8-15 are circuit schematic diagrams of a preferred embodiment of the test pencil of the present invention, wherein, fig. 8 shows the connection relationship between the microcontroller and each module, fig. 9 is a circuit schematic diagram of the non-contact voltage signal acquisition module, the contact voltage signal acquisition module and the phase sequence signal acquisition module, fig. 10 is a circuit schematic diagram of the key module, fig. 11 is a circuit schematic diagram of the power supply module, fig. 12 is a circuit schematic diagram of the function indicator light module, fig. 13 is a circuit schematic diagram of the lighting lamp module, fig. 14 is a circuit schematic diagram of the dual-color backlight module, and fig. 15 is a circuit schematic diagram of the buzzer alarm module.

Fig. 16 is a first embodiment of the display unit of the test pencil of fig. 1.

Fig. 17 is a second embodiment of the display unit of the test pencil of fig. 1.

Fig. 18 is a third embodiment of the display unit of the test pencil of fig. 1.

In order to make the technical solution of the present invention clearer and more clear, the following detailed description will be made with reference to the accompanying drawings.

Detailed Description

Referring to fig. 1 to 7, a preferred embodiment of the present invention provides a test pencil, which includes a pen-shaped housing 51, a circuit board 52, a microcontroller U1, a voltage measurement mode switching unit 53, a sensing unit 54, and a display unit 55. The circuit board 52 is provided with a sensing signal input point 520, a non-contact voltage (NCV) signal acquisition module 521, a Contact Voltage (CVT) signal acquisition module 522 and a switch SW1, the circuit board 52 is arranged in the pen-shaped housing 51, and the sensing unit 54 is arranged at the front end of the pen-shaped housing 51 and contacts with the sensing signal input point 520; the microcontroller U1 is mounted on the circuit board 52 and the display unit 55 is mounted on the pen housing 51 and connected to the microcontroller U1.

The voltage measurement mode switching unit 53 is provided on the pen-shaped housing 51, and operates the switch SW1 to switch between a noncontact voltage measurement mode and a contact voltage measurement mode;

the non-contact voltage signal acquisition module 521 is configured to acquire a voltage to be detected in a non-contact manner through the sensing unit 54 in a non-contact voltage measurement mode, and output the acquired signal to the microcontroller U1;

the contact voltage signal collecting module 522 is configured to collect a voltage to be detected in a contact manner through the sensing unit 54 in a contact voltage measurement mode, and output a collected signal to the microcontroller U1;

the microcontroller U1 is configured to process a signal input by the non-contact voltage signal acquisition module 521/the contact voltage signal acquisition module 522 to obtain a voltage to be detected, and send a corresponding first control signal to the display unit 55 according to the obtained voltage to be detected;

the display unit 55 is configured to display a voltage strength identifier corresponding to the acquired voltage to be detected according to the first control signal, so that a user can know the strength of the current voltage detected by the test pencil.

The utility model discloses test pencil through setting up non-contact voltage (NCV) signal acquisition module 521, Contact Voltage (CVT) signal acquisition module 522 and change over switch SW1, only needs to carry a test pencil, can enough realize the non-contact of voltage and measure, can realize the contact measurement of voltage again, and it is more convenient to carry and use. When measuring the voltage, non-contact measurement can be selected, and contact measurement is adopted when the voltage is determined to be within the safety range, so that the personal safety of a user can be guaranteed, and higher measurement accuracy is achieved.

In this embodiment, the pen-shaped housing 51 includes a hollow pen body 56, a cap 57 disposed at the front end of the pen body 56, and a battery cover 58 disposed at the rear end of the pen body 56, the circuit board 52 is disposed in the pen body 56 of the pen-shaped housing 51, and the sensing unit 54 is disposed on the cap 57 of the pen-shaped housing 51 and contacts with the sensing signal input point 520. The pen body 56 and the cap 57 may be made of an insulating material.

An annular engaging groove 561 is formed in one end face, facing the cap 57, of the pen body 56, and the rear end of the cap 57 is inserted into the engaging groove of the pen body 56 and can be bonded together through gluing or ultrasonic welding. The battery cover 58 is connected with the rear end of the pen body 56 through threads.

In the present embodiment, the switch SW1 is a tact switch, and the tact switch (switch SW1) is turned on, released, or turned off by pressing the tact switch (switch SW1) by the voltage measurement mode switching unit 53.

The voltage measurement mode switching unit 53 includes a sliding rod 59 and a pressing plate 60, a first through hole 511 is formed in the pen-shaped housing 51 corresponding to the outer end of the sliding rod 59, a second through hole 601 is formed in the pressing plate 60 corresponding to the inner end of the sliding rod 59, the outer end of the sliding rod 59 passes through the first through hole 511 to extend out of the pen-shaped housing 51, the inner end of the sliding rod 59 passes through the second through hole 601 for pressing a tact switch (a switch SW1), and the sliding rod 59 is mounted on the pen-shaped housing 51 through the pressing plate 60 and can slide in the first through hole 511 and the second through hole 601.

In this embodiment, the first through hole 511 is provided on the front end plate of the cap 57, the sliding rod 59 is mounted inside the front end plate of the cap 57 through the pressing piece 60, and the outer end of the sliding rod 59 protrudes outward from the front end plate of the cap 57. The test pencil further comprises a pencil cap 61 for covering the cap 57, the pencil cap 61 is used for pressing the outer end of the sliding rod 59 when the front end of the cap 57 is covered, so that the inner end of the sliding rod 59 moves towards the tact switch (switch SW1) to press the tact switch (switch SW1), and the tact switch (switch SW1) is pressed and then switched on to be switched to a non-contact voltage measurement mode. When the cap 61 is removed from the cap 57, the force applied to the outer end of the slide rod 59 is removed, and the tact switch (the switch SW1) is restored to the off state by its own elastic force, and is switched to the contact voltage measuring mode.

Realize pressing at the front end of caping 57 through cap 61 shroud tact switch (change over switch SW1) switches to non-contact voltage measurement mode, and cap 61 can adopt insulating material to make, like this, under non-contact voltage measurement mode, can carry out insulation protection to induction element 54 through cap 61, avoid induction element 54 and the electrified object direct contact that awaits measuring, prevent to cause because of the maloperation and burn the test pencil to and ensure user personal safety.

When the tact switch is used as the changeover switch SW1, the operation of pressing the tact switch (changeover switch SW1) by the voltage measurement mode changeover unit 53 is not limited to the manner in which the cap 61 is pressed in the present embodiment. In other embodiments, the first through hole 511 may be disposed on the pen body 56 of the pen-shaped housing 51, in which case, the installation direction of the sliding rod 59 needs to be adjusted accordingly, and the sliding rod 59 is installed on the pen body 56 through the pressing sheet 60, so that the user can press the tact switch (the switch SW1) to switch on by pressing the sliding rod 59 with a hand, and switch to the non-contact voltage measurement mode, and the tact switch (the switch SW1) is reset to off by releasing the hand, and then switch to the contact voltage measurement mode; alternatively, a button is provided on the pen body 56 of the pen-shaped housing 51 corresponding to the slide bar 59, and the tact switch (the switch SW1) is pressed to be turned on by pressing the button against the slide bar 59, and the mode is switched to the noncontact voltage measurement mode, and the tact switch (the switch SW1) is reset to be turned off by releasing the hand, and the mode is switched to the contact voltage measurement mode. When the tact switch (changeover switch SW1) is not pressed with the cap 61, the cap 61 may be kept or the cap 61 may be removed.

The switch SW1 is not limited to the tact switch, and in other embodiments, other types of switches can be used, such as a toggle switch, in which case, the voltage measurement mode switching unit 53 can be replaced by a toggle key, which can be disposed on the pen body 56, and by operating the toggle key, the toggle switch (the switch SW1) can be controlled to be turned on and off, so as to switch between the non-contact voltage measurement mode and the contact voltage measurement mode. In this case, the cap 61 may be kept or the cap 61 may be removed.

In this embodiment, the outer surface of the front end of the cap 57 is formed with an external thread 571, the inner surface of the rear end of the cap 61 is correspondingly formed with an internal thread (not labeled), and the cap 61 is covered on the cap 57 without falling off by rotating the cap 61 to combine the internal thread of the cap 61 with the external thread of the cap 57.

The combination of the cap 61 and the cap 57 is not limited to this embodiment, and in other embodiments, other detachable connection manners may also be adopted, for example, a first fastening structure (e.g., a fastening block/fastening position) is provided on the cap 57, and a second fastening structure (e.g., a fastening position/fastening block) is correspondingly provided on the cap 61, and by inserting and/or rotating the cap 61, the second fastening structure of the cap 61 is combined with or separated from the first fastening structure of the cap 57, so as to cover the cap 61 on the cap 57 or remove the cap 61 from the cap 57.

In this embodiment, a protruding ring 591 is further formed in the middle of the sliding rod 59, and the protruding ring 591 is sandwiched between the front end plate of the cover head 57 and the pressing sheet 60 to limit the sliding stroke of the sliding rod 59, so as to prevent the sliding rod 59 from falling off from the first through hole 511 and the second through hole 601, and prevent the sliding rod 59 from pressing the tact switch (the switch SW1) too much to damage the tact switch (the switch SW 1).

In this embodiment, the sensing unit 54 includes a screwdriver seat 541 and a screwdriver rod 542, the screwdriver seat 541 is installed on the cap 57, the screwdriver rod 542 is installed on the screwdriver seat 541 and extends out of the cap 57, when the pen cap 61 covers the cap 57, the screwdriver rod 542 is covered in the pen cap 61, and the screwdriver seat 541 and the screwdriver rod 542 are electrically connected to the sensing signal input point 520. The screwdriver blade 541 and the screwdriver shaft 542 may be made of a conductive material, such as metal.

In this embodiment, the sensing unit 54 further includes a flat sensing piece 543, the outer end of the pen cap 61 is provided with a flat receiving portion 611, the sensing piece 543 is disposed in the receiving portion 611 of the pen cap 61, and the sensing piece 543 is used for electrically connecting with the screwdriver rod 542 when the pen cap 61 covers the cap 57. Through the arrangement of the flat sensing piece 543 and the flat accommodating portion 611, when the socket is subjected to non-contact voltage measurement, the flat sensing piece 543 can be conveniently inserted into the jack of the socket, so that the sensing piece 543 is close to the wiring terminal of the socket as far as possible, and accuracy of the non-contact voltage measurement can be improved.

Further, a compression spring 544 is connected to the sensing piece 543, and the compression spring 544 is used for electrically connecting the sensing piece 543 and the screwdriver rod 542 when the pen cap 61 covers the cap 57. Through setting up compression spring 544, can be so that the electrically conductive connection between response piece 543 and screwdriver pole 542 is more reliable to improve non-contact voltage measurement's accuracy. In other embodiments, the compression spring 544 may not be disposed, and one end of the sensing piece 543 close to the screwdriver rod 542 is bent to form a spring sheet, so that the conductive connection between the sensing piece 543 and the screwdriver rod 542 is more reliable by the contact between the screwdriver rod 542 and the spring sheet.

Furthermore, the sensing piece 543 protrudes toward one side thereof with a spring 5431, and the sensing piece 543 can be tightly combined with the receiving portion 611 when inserted into the receiving portion 611 of the pen cap 61 by the spring 5431, and is not easily detached from the receiving portion 611.

Furthermore, the outer circumferential surface of the pen cap 61 is further provided with anti-slip protrusions 612, which can play a role of anti-slip when the pen cap 61 is rotated.

In this embodiment, the screwdriver rod 542 is detachably mounted on the screwdriver seat 541, two ends of the screwdriver rod 542 are respectively formed with

screwdriver bits

5421 and 5422, wherein one of the screwdriver bits 5421 has a straight head shape, and the other screwdriver bit 5422 has a cross head shape. The arrangement form of the screwdriver bit is not limited, and in other embodiments, the screwdriver bit may be formed at only one end of the screwdriver rod 542; the head shape of the screwdriver head can also be in a shape like Chinese character 'mi', star, square head, hexagonal head or Y shape; the heads of the screwdriver bits at the two ends of the screwdriver rod 542 may be the same, and the sizes of the heads may be the same or different. In other embodiments, the screwdriver rod 542 may be non-detachably mounted on the screwdriver seat 541.

The screwdriver holder 541 is provided with a mounting hole 5411, the mounting hole 5411 may be a polygonal hole or a flat hole, in this embodiment, the mounting hole 5411 is a regular hexagonal hole, and the cross section of the screwdriver rod 542 is matched with the mounting hole 5411 of the screwdriver holder 541 in shape, so that the screwdriver rod 542 can be prevented from rotating with respect to each other after being mounted in the mounting hole 5411 of the screwdriver holder 541.

In this embodiment, the circuit board 52 is provided with a contact sheet 62 contacting the sensing signal input point 520, a contact spring 63 is disposed on a side of the contact sheet 62 facing the screwdriver seat 541, and the contact spring 63 is used for electrically connecting with the sensing unit 54, specifically, electrically connecting with the screwdriver seat 541 of the sensing unit 54.

Further, a blind hole 5412 is formed in one side, facing the contact spring 527, of the screwdriver base 541, a magnetic attraction block 64 is arranged in the blind hole 5412, the contact spring 527 is electrically connected with the screwdriver base 541 through the magnetic attraction block 64, the screwdriver rod 542 can be attracted, and the screwdriver rod 542 is prevented from falling from the screwdriver base 541.

In this embodiment, a power supply module 526 is further disposed on the circuit board 52, and the power supply module 526 includes a battery BAT, and the battery BAT is disposed in the pen body to supply power to the entire test pencil.

In this embodiment, the circuit board 52 is further provided with a key module 527, and the key module 527 includes a power key PWKEY for controlling the on and off of the test pencil.

Further, the key module 527 further includes a sensitivity key SKEY, where the sensitivity key SKEY is used to switch the sensitivity range of the test pencil.

In this embodiment, a lighting lamp module 528 is further disposed on the circuit board 52, the lighting lamp module 528 includes a lighting lamp L ED2 for lighting, so as to be convenient for use in a dark environment, the lighting lamp L ED2 extends into the cover head 57, and a light-emitting window 572 is disposed at a front end of the cover head 57 corresponding to the lighting lamp L ED 2.

In this embodiment, the sensitivity key SKEY is also used to turn on and off the illumination lamp L ED2, i.e. the sensitivity key SKEY is a function multiplexing key, and when the function multiplexing key is implemented, the sensitivity range can be switched by short pressing (for example, pressing time <1 second), and the illumination lamp L ED2 can be controlled to be switched by long pressing (for example, pressing time >2 seconds).

In this embodiment, a function indicator module 532 is further disposed on the circuit board 52, the function indicator module 532 includes a power indicator L ED3 indicating power on, and the power indicator L ED3 is configured to be illuminated when the power is on.

The display unit 55 may use an L CD display screen, a digital tube or a L ED lamp to display the voltage intensity indication.

When the display unit 55 adopts an L CD display screen or a nixie tube, the voltage intensity indicator may be an analog bar, and the display unit 55 displays the analog bars of which the number corresponds to the acquired voltage to be detected according to the first control signal, or the voltage intensity indicator may be a voltage value.

When the display unit 55 uses L ED lamps, a plurality of L ED lamps of the same color can be used, the voltage intensity is indicated by the number of illuminated L ED lamps, the smaller the number of illuminated L ED lamps, the smaller the indicated voltage, the larger the number of illuminated L ED lamps, the larger the indicated voltage, the L ED lamps or L ED lamp groups which can emit a plurality of types (not less than two types), the voltage intensity is indicated by the color of the illuminated L ED lamps, and the corresponding voltage intensity is indicated by the different color of the L ED lamps or the L ED lamp groups.

In this embodiment, the display unit 55 includes L CD display panels 551, L CD display panels 551, and lenses 65 are disposed on the outer surfaces of the CD display panels 551, the circuit board 52 is further provided with a dual-color backlight module 529, the dual-color backlight module 529 includes two light emitting diodes emitting different colors, i.e., a ninth light emitting diode L ED9 and a tenth light emitting diode L ED10, and two backlights with different colors, such as a green backlight and a red backlight, can be lit for the L CD display panel 551 through the dual-color backlight module 529.

The lens 65 covers the area of the key module 527, and through holes 651 are respectively formed in the lens 65 corresponding to the keys (the power key PWKEY, the sensitivity key SKEY, and the function switching key FUNC) of the key module 527 for the keys to pass through.

The display unit 55 is also used to display the corresponding text and/or symbol (e.g., display "NCV") in the non-contact voltage measurement mode, and to display the corresponding text and/or symbol (e.g., display "CVT") in the contact voltage measurement mode.

The display unit 55 is further configured to display a battery BAT undervoltage sign to indicate that the battery BAT is undervoltage when the battery BAT is undervoltage.

In this embodiment, the circuit board 52 is further provided with a buzzer alarm module 530, the buzzer alarm module 530 includes a buzzer BUZ, the microcontroller U1 is further configured to control the buzzer to emit a frequency sound corresponding to the acquired voltage to be detected according to the acquired voltage to be detected,

in this embodiment, the buzzer alarm module 530 may further include a signal lamp L ED1, and the microcontroller U1 is further configured to control the signal lamp L ED1 to illuminate the brightness corresponding to the acquired voltage to be detected or control the signal lamp L ED1 to emit the frequency of flashing corresponding to the acquired voltage to be detected.

In the embodiment, when the test pencil is used, all the indicator lamps of the function indicator lamp module 532 are lighted for a preset time (for example, 0.5 second) when the power key PWKEY is pressed for starting, a non-contact voltage (NCV) measurement mode is entered after the test pencil is started, the two-color backlight module 529 lights the green backlight of the L CD display screen 551, and the L CD display screen 551 displays the interface A (the actual backlight of the interface A is green) in the graph 16.

When a non-contact voltage (NCV) measurement mode is performed:

1. the buzzer BUZ prompts sound to be divided into three stages: slow speed prompt, medium speed prompt and fast prompt;

2. the sensitivity range comprises a high sensitivity range of 12V-1000V and a low sensitivity range of 48V-1000V.

When the measurement is carried out under the high-sensitivity measuring range of 12V-1000V, the high-sensitivity measuring range of 12V-1000V is divided into a plurality of sections, different colors of backlight of a L CD display screen 551 are lightened through a two-color backlight module 529, different levels of prompting sound are sent out through a buzzer BUZ, and/or different numbers of analog bars are displayed through a L CD display screen 551 to represent the voltage section where the detection voltage is located, and a preferable example is given as follows:

a) when 12V < detection voltage <48V (first segment interval), the two-color backlight module 529 lights the green backlight of the L CD display 551, the buzzer BUZ prompts slowly, the L CD display 551 displays the interface B (the actual backlight of the interface B is green) as shown in fig. 16, that is, displays a corresponding number of analog bars to indicate the detection voltage;

b) when the detection voltage is less than or equal to 48V and less than 90V (in the second section), the two-color backlight module 529 lights the green backlight of the L CD display screen 551, the buzzer BUZ prompts at a medium speed, and the L CD display screen 551 displays an interface C (the actual backlight of the interface C is green) as shown in FIG. 16, that is, displays a corresponding number of simulation bars to represent the detection voltage;

c) when the voltage is not less than 90V (the third section interval), the two-color backlight module 529 lights the red backlight of the L CD display 551, the buzzer BUZ quickly prompts, and the L CD display 551 displays the interface D (the actual backlight of the interface D is red) as shown in fig. 16, that is, displays a corresponding number of analog bars to represent the magnitude of the detected voltage.

When measuring under the low-sensitivity range of 48V-1000V, dividing the low-sensitivity range of 48V-1000V into multiple sections, lighting different colors of backlight of L CD display screen through a two-color backlight module, giving out different levels of prompting sound through a buzzer BUZ, and/or displaying different numbers of analog bars through a L CD display screen to represent the voltage section where the detection voltage is located, as the following gives a preferable example:

d) when the detection voltage is less than 90V (in the first section interval), the two-color backlight module 529 lights the green backlight of the L CD display 551, the buzzer BUZ prompts slowly, the L CD display 551 displays the interface B (the actual backlight of the interface B is green) in the graph of FIG. 16, namely, the simulation bars with corresponding quantity are displayed to represent the detection voltage;

e) when the detection voltage is more than or equal to 90V and less than 150V (in the second section), the two-color backlight module 529 lights the green backlight of the L CD display screen 551, the buzzer BUZ prompts at a medium speed, and the L CD display screen 551 displays an interface C (the actual backlight of the interface C is green) as shown in FIG. 16;

f) when the detection voltage is less than or equal to 150V (in the third section interval), the two-color backlight module 529 lights the red backlight of the L CD display 551, the buzzer BUZ prompts quickly, the L CD display 551 displays the interface D (the actual backlight of the interface D is green) in the graph 16, namely, the simulation bars with corresponding quantity are displayed to represent the detection voltage.

In this embodiment, the threshold of the sensitivity segment is given as an example, and is not limited to this, and in the practical application process, the threshold may be adaptively adjusted according to specific needs.

In this embodiment, the circuit board 52 is provided with a grounding point GND, the pen-shaped housing 51 is provided with a grounding contact piece 66 electrically connected to the grounding point GND, and when the measurement is performed in the Contact Voltage (CVT) measurement mode, the pen cap 61 is removed, the sensing unit 54 is contacted with the measured object, and the measuring person contacts the grounding contact piece 66 with his hand to form a ground line through the human body, thereby realizing the Contact Voltage (CVT) measurement.

When the Contact Voltage (CVT) measurement mode is used for measurement, the voltage detection range is 12-250V, the voltage detection range is divided into a plurality of sections, different color backlights of a L CD display screen 551 are lightened through a two-color backlight module 529, and/or different numerical values are displayed through a L CD display screen 551 to represent the voltage section of the detection voltage, and a preferable example is given as follows:

1) when the detection voltage is less than 12V (in the first section), the two-color backlight module 529 lights the green backlight of the L CD display 551, and the L CD display 551 displays the interface A (the actual backlight of the interface A is green) in FIG. 17, that is, the voltage value 000V and the AC symbol are displayed;

2) when the detection voltage is less than or equal to 12V and less than 50V (in the second section), the two-color backlight module 529 lights the green backlight of the L CD display 551, and the L CD display 551 displays an interface B (the actual backlight of the interface B is green) as shown in FIG. 17, that is, a voltage value 012V and an alternating current symbol are displayed;

3) when the detection voltage is less than or equal to 50V and less than 250V (a third section interval), the two-color backlight module 529 lights the red backlight of the L CD display screen 551, and the L CD display screen 551 displays an interface C (the actual backlight of the interface C is red) as shown in FIG. 17, namely, a voltage value of 050V, an alternating current symbol and a high-voltage lightning symbol are displayed;

4) when the voltage is not less than 250V and the detection voltage is not more than the fourth segment, the bicolor backlight module 529 lights the red backlight of the L CD display 551, and the L CD display 551 displays the interface D (the actual backlight of the interface D is red) shown in fig. 17, that is, the voltage value is 250V, the ac symbol and the high-voltage lightning symbol.

In this embodiment, the threshold of the voltage segment is given as an example, and is not limited to this, and in the practical application process, the threshold may be adaptively adjusted according to specific needs.

In this embodiment, the circuit board 52 is further provided with a phase sequence signal acquisition module 525, and the key module 527 includes a function switching key FUNC for switching between a non-contact voltage measurement mode and a non-contact phase sequence (NCP) measurement mode.

The function indicator lamp module 532 includes a phase sequence indicator lamp L ED4 indicating a non-contact phase sequence (NCP) measurement mode, and a phase sequence indicator lamp L ED4 is lit when switching to the non-contact phase sequence (NCP) measurement mode.

The phase sequence signal acquisition module 525 is configured to acquire a phase sequence of a three-phase line to be detected in a non-contact manner through the sensing unit 54 in a non-contact phase sequence measurement mode, and output an acquired signal to the microcontroller U1;

the microcontroller U1 is further configured to process a signal input by the phase sequence signal acquisition module 525 to obtain a phase sequence detection result, and send a corresponding second control signal to the display unit 55 according to the phase sequence detection result;

the display unit 55 is configured to correspondingly display the phase sequence detection result according to the second control signal.

In this embodiment, the display unit 55 is further configured to display corresponding characters and/or symbols in the non-contact phase sequence measurement mode, for example, displaying "NCP" indicating the non-contact phase sequence measurement mode, displaying a right-handed symbol in the measurement result as a positive phase sequence, and displaying a left-handed symbol in the measurement result as a negative phase sequence, the two-color backlight module 529 is further configured to illuminate L different color backlights of the CD display 551 when displaying the phase sequence measurement result to respectively indicate a positive phase sequence and a negative phase sequence, for example, a green backlight indicating a positive phase sequence and a red backlight indicating a negative phase sequence.

In the contact voltage measurement mode, pressing the function switching key FUNC is ineffective, i.e., it is not possible to switch to the non-contact phase sequence measurement mode at this time. To enter the non-contact phase sequence measuring mode, the cap 61 is covered, the contact voltage measuring mode is switched to the non-contact voltage measuring mode, in the non-contact voltage measuring mode, the non-contact phase sequence measuring mode can be switched to by pressing the function switching key FUNC,

in the present embodiment, the display unit 55 includes an L CD display 551, and displays the phase sequence measurement process and the result through the L CD display 551.

The steps for performing the non-contact phase sequence measurement are as follows:

in the noncontact voltage measurement mode, by pressing the function switching key FUNC, the noncontact phase sequence measurement mode is entered, and the L CD display screen 551 displays the interface a as in fig. 17, with the character "a" appearing blinking, and with the symbol "NCP" indicating the noncontact phase sequence measurement mode;

the sensing unit 54 of the test pencil is close to the first line of the three-phase line to be detected, when the sampling of the phase sequence signal acquisition module 525 is completed, the buzzer BUZ clicks once, the L CD display 551 displays the interface B as shown in FIG. 17, a flashing character "B" appears, and a symbol "NCP" indicating a non-contact phase sequence measurement mode is displayed;

the sensing unit 54 of the test pencil is close to the second line of the three-phase line to be detected, similarly, after the sampling of the phase sequence signal acquisition module 525 is completed, the buzzer BUZ clicks once, and the L CD display 551 displays the interface C as shown in fig. 17, and a flashing character "C" appears, and a symbol "NCP" indicating a non-contact phase sequence measurement mode is displayed;

the sensing unit 54 of the test pencil is close to the third line of the three-phase line to be tested, similarly, after the sampling of the phase sequence signal acquisition module 525 is completed, the buzzer BUZ clicks a long sound, the L CD display 551 displays the phase sequence detection result and different phase sequence detection results, the L CD display 551 displays different interfaces, when the phase sequence measurement result is a reverse phase sequence, the L CD display 551 displays an interface D as shown in FIG. 17, the bicolor backlight module 529 lights a red backlight of the L CD display 551, when the phase sequence detection result is a positive phase sequence, the L CD display 551 displays an interface E as shown in FIG. 17, the bicolor backlight module 529 lights a green backlight of the L CD display 551, and when the phase sequence detection result is an error, the L CD display 551 displays an interface F as shown in FIG. 17.

When the phase sequence detection needs to be carried out again, the sensitivity key SKEY is pressed, the previous measurement result can be cleared, and then the detection is carried out according to the non-contact phase sequence measurement steps.

When the phase sequence detection is finished, pressing the function switching key FUNC can switch back to the non-contact voltage measurement mode.

In the phase sequence detection process, the power-off can be carried out at any time, and the non-contact voltage measurement mode can be returned at any time by pressing a function switching key FUNC; or pressing the sensitivity key SKEY interrupts the current measurement to resume the measurement.

In this embodiment, a phase sequence signal acquisition module 525 is further included, so that the test pencil has a phase sequence detection function. In other embodiments, the phase-sequence signal acquisition module 525 may not be included, depending on the actual requirement.

Fig. 8-15 are schematic circuit diagrams of a preferred embodiment of the test pencil of the present invention, wherein fig. 8 shows a connection relationship between the microcontroller U1 and each module, fig. 9 is a schematic circuit diagram of the non-contact voltage signal acquisition module 521, the contact voltage signal acquisition module 522 and the phase sequence signal acquisition module 525, fig. 10 is a schematic circuit diagram of the key module 527, fig. 11 is a schematic circuit diagram of the power supply module 526, fig. 12 is a schematic circuit diagram of the function indicator light module 532, fig. 13 is a schematic circuit diagram of the lighting lamp module 528, fig. 14 is a schematic circuit diagram of the two-color backlight module 529, and fig. 15 is a schematic circuit diagram of the buzzer alarm module 530.

In the present embodiment, as shown in fig. 8, the model of the microcontroller U1 is preferably CS77P35, but not limited to this, and the microcontroller U1 may be other chips capable of implementing the same function. The model CS77P35 microcontroller U1 has 38 pins, each having the name shown in fig. 8.

L the CD display 551 is connected to pins 23-38 of the microcontroller U1, and the microcontroller U1 controls the display of L the CD display 551.

As shown in fig. 11, for a schematic circuit diagram of the power supply module 526, the power supply module 526 includes a battery BAT, a fourth transistor Q4, an eleventh resistor R11, a fifth capacitor C5, and a sixth capacitor C6, a negative electrode of the battery BAT is grounded, a positive electrode of the battery BAT is connected to a drain D of the fourth transistor Q4, one end of the eleventh resistor R11 is grounded and connected to a negative electrode of the battery BAT, the other end of the eleventh resistor R11 is connected to a gate G of the fourth transistor Q4, one end of the fifth capacitor C5 is grounded, the other end of the fifth capacitor C5 is connected to a source S of the fourth transistor Q4, one end of the sixth capacitor C6 is grounded, the other end of the sixth capacitor C6 is connected to a source S of the fourth transistor Q4, and the source S of the fourth transistor Q4 is used for outputting the power supply voltage VDD.

The supply voltage VDD is connected to a 7 th pin AVDD of the microcontroller U1, and the fourth transistor Q4 is a P-channel MOS fet.

Fig. 9 is a schematic circuit diagram of the non-contact voltage signal acquisition module 521, the contact voltage signal acquisition module 522, and the phase sequence signal acquisition module 525.

The non-contact voltage signal acquisition module 521 comprises a first resistor R1, a second resistor R2 and an eighteenth resistor R18, one end of a switch SW1 is connected with the sensing signal input point 520, one end of the eighteenth resistor R18 is connected with the other end of the switch SW1, the other end of the eighteenth resistor R18 is connected with a pin 10 AIN1 of the microcontroller U1, one end of a first resistor R1 is connected with the other end of the eighteenth resistor R18, the other end of the first resistor R1 is connected with a pin 8 VS/REF of the microcontroller U1, one end of a second resistor R2 is connected with the other end of the eighteenth resistor R18, and the other end of the second resistor R2 is grounded.

The contact voltage signal acquisition module 522 includes a thirteenth resistor R13, a fourteenth resistor R14, a fifteenth resistor R15, a sixteenth resistor R16, a seventeenth resistor R17, a twenty-second resistor R22, a twenty-third resistor R23, a twenty-fourth resistor R24, a twenty-fifth resistor R25, a twenty-sixth resistor R26 and a twenty-seventh resistor R27.

One end of a thirteenth resistor R13 is connected between the sensing signal input point 520 and one end of the switch SW1, the other end of the thirteenth resistor R13 is connected with one end of a fourteenth resistor R14, one end of the twenty-second resistor R22 is grounded, the other end of the twenty-second resistor R22 is connected with one end of a seventeenth resistor R17, the fourteenth resistor R14, the fifteenth resistor R15, the sixteenth resistor R16 and the seventeenth resistor R17 are sequentially connected in series, one end of a twenty-third resistor R23 is connected between the sixteenth resistor R16 and the seventeenth resistor R17, and the other end of the twenty-third resistor R23 is connected with the 11 th pin PT24 of the microcontroller U1.

One end of a twenty-fourth resistor R24, a twenty-fifth resistor R25, a twenty-sixth resistor R26 and a twenty-seventh resistor R27 which are sequentially connected in series is connected with the grounding point GND, and the other end of the twenty-fourth resistor R24, the twenty-fifth resistor R25, the twenty-sixth resistor R26 and the twenty-seventh resistor R27 which are sequentially connected in series is grounded.

The phase sequence signal acquisition module 525 comprises a first comparator U3-A, a first capacitor C1, a second comparator U2-B, a seventh capacitor C7, an eighth capacitor C8, an eighth resistor R8, a ninth resistor R9, a tenth resistor R10 and a third comparator U2-A. The positive pole input end of a first comparator U3-A is connected with the other end of the switch SW1, the negative pole input end of a first comparator U3-A is connected with the output end of the first comparator U3-A, one end of a first capacitor C1 is connected with the output end of the first comparator U3-A, the other end of a first capacitor C1 is connected with the negative pole input end of a second comparator U2-B, one end of a seventh capacitor C7 is connected with the negative pole input end of the second comparator U2-B, the other end of the seventh capacitor C7 is connected with the output end of the second comparator U2-B, the positive pole input end of the second comparator U2-B is grounded, one end of an eighth resistor R8 is connected with the negative pole input end of the second comparator U2-B, the other end of an eighth resistor R8 is grounded, one end of an eighth capacitor C8 is connected with the output end of the second comparator U2-B, the other end of the eighth capacitor C8 is connected with the positive input end of the third comparator U2-A, one end of a ninth resistor R9 is connected between the other end of the eighth capacitor C8 and the positive input end of the third comparator U2-A, the other end of the ninth resistor R9 is grounded and connected with the other end of the eighth resistor R8, one end of a tenth resistor R10 is connected between the other end of the eighth capacitor C8 and the positive input end of the third comparator U2-A, the other end of the tenth resistor R10 is connected with the supply voltage VDD, the negative input end of the third comparator U2-A is grounded and connected with the positive input end of the second comparator U2-B, and the output end of the third comparator U2-A is connected with the 14 th pin PT15 of the microcontroller U1.

As shown in fig. 10, which is a schematic circuit diagram of the key module 527, the key module 527 includes a power key PWWKEY, a sensitivity key SKEY and a function switch key FUNC, one end of the power key PWWKEY is grounded, the other end of the power key PWWKEY is connected to the 18 th pin PT21 of the microcontroller U1, one end of the sensitivity key SKEY is grounded, the other end of the sensitivity key SKEY is connected to the 20 th pin PT23 of the microcontroller U1, one end of the function switch key FUNC is grounded, and the other end of the function switch key FUNCY is connected to the 21 st pin PT26 of the microcontroller U1.

As shown in fig. 12, which is a schematic circuit diagram of the function indicator light module 532, the function indicator light module 532 includes a twelfth resistor R12, a power indicator light L ED3 and a phase sequence indicator light L ED4, one end of the twelfth resistor R12 is connected to the supply voltage VDD, the other end of the twelfth resistor R12 is connected to the anode of the power indicator light L ED3 and is also connected to the anode of the phase sequence indicator light L ED4, the cathode of the power indicator light L ED3 is connected to the 3 rd pin 12 of the microcontroller U1, and the cathode of the phase sequence indicator light PT L ED4 is connected to the 4 th pin PT13 of the microcontroller U1.

As shown in fig. 12, which is a schematic circuit diagram of the lighting lamp module 528, the lighting lamp module 528 includes a sixth resistor R6, a lighting lamp L ED2, a second transistor Q2, a seventh resistor R7., one end of the sixth resistor R6 is connected to the supply voltage VDD, the other end of the sixth resistor R6 is connected to the anode of the lighting lamp L ED2, the cathode of the lighting lamp L ED2 is connected to the collector of the second transistor Q2, the emitter of the second transistor Q2 is grounded, one end of the seventh resistor R7 is connected to the base of the second transistor Q2, the other end of the seventh resistor R7 is connected to the pin PT22 of the 19 th pin of the microcontroller U1, and the second transistor Q21 is an NPN-type transistor.

As shown in fig. 14, the two-color backlight module 529 is a schematic circuit diagram of the two-color backlight module 529, where the two-color backlight module 529 includes a nineteenth resistor R, a third triode Q, a ninth light emitting diode ED, a tenth light emitting diode ED, a fifth triode Q, a twentieth resistor R and a twenty-first resistor R, one end of the nineteenth resistor R is connected to a pin 15 PT of the microcontroller U, the other end of the nineteenth resistor R is connected to a base of the third triode Q, an emitter of the third triode Q is grounded, a collector of the third triode Q is connected to a cathode of the ninth light emitting diode ED, an anode of the ninth light emitting diode ED is connected to one end of the twentieth resistor R, the other end of the twentieth resistor R is connected to the power supply voltage VDD, one end of the twenty-first resistor R is connected to a pin 16 PT of the microcontroller U, the other end of the twenty-first resistor R is connected to a base of the fifth triode Q, an emitter of the fifth triode Q is grounded, a collector of the fifth triode Q is connected to a cathode of the tenth light emitting diode ED, an anode of the tenth light emitting diode is connected to one end of.

As shown in fig. 15, the circuit schematic diagram of the buzzer alarm module 530 is shown, the buzzer alarm module 530 includes a fourth resistor R4, a first triode Q1, a buzzer BUZ, a third resistor R3, a fifth resistor R5 and a signal lamp L ED1, one end of the fourth resistor R4 is connected to the 22 nd pin PT27 of the microcontroller U1, the other end of the fourth resistor R4 is connected to the base of the first triode Q1, the emitter of the first triode Q1 is grounded, the collector of the first triode Q1 is connected to one end of the buzzer BUZ, the other end of the buzzer BUZ is connected to one end of the third resistor R3, the other end of the third resistor R3 is connected to a supply voltage VDD, the signal lamp L ED1 is a light emitting diode, the cathode of the signal lamp L1 is connected between the collector of the first triode Q1 and one end of the buzzer BUZ, the anode of the signal lamp L ED1 is connected to one end of the fifth resistor R5, the fifth resistor R5 is connected to the other end of the third resistor ED 3.

The circuit schematic diagrams of fig. 8-15 are only examples, the circuit structures of the non-contact voltage signal collection module 521, the contact voltage signal collection module 522, the phase sequence signal collection module 525, the key module 527, the power supply module 526, the function indicator lamp module 532, the two-color backlight module 529, and the buzzer alarm module 530 during actual use are not limited to this, components in each circuit can be adaptively added, deleted, and replaced as needed, as long as the functions of each module can be actually included in the protection scope of the present invention.

The above only is the preferred embodiment of the present invention, not limiting the scope of the present invention, all the equivalent structures or flow changes made by the contents of the specification and the drawings, or directly or indirectly applied to other related technical fields, are included in the same way in the protection scope of the present invention.

Claims

1. A test pencil is characterized by comprising a pencil-shaped shell, a circuit board, a microcontroller, a voltage measurement mode switching unit, a sensing unit and a display unit, wherein the circuit board is provided with a sensing signal input point, a non-contact voltage signal acquisition module, a contact voltage signal acquisition module and a switch; the microcontroller is mounted on the circuit board, and the display unit is mounted on the pen-shaped housing and connected with the microcontroller;

2. The test pencil of claim 1 wherein the pencil housing comprises a hollow pencil body and a cap disposed at a front end of the pencil body, the circuit board is disposed in the pencil body of the pencil housing, and the sensing unit is disposed on the cap of the pencil housing and contacts the sensing signal input point.

3. The test pencil of claim 2 wherein the switch is a tact switch, and pressing the tact switch by the voltage measurement mode switching unit turns the tact switch on and off.

4. The test pencil of claim 3, wherein the voltage measuring mode switching unit comprises a slide bar and a pressing plate, the pen-shaped housing is provided with a first through hole corresponding to an outer end of the slide bar, the pressing plate is provided with a second through hole corresponding to an inner end of the slide bar, the outer end of the slide bar passes through the first through hole to protrude outside the pen-shaped housing, the inner end of the slide bar passes through the second through hole for pressing a tact switch, and the slide bar is mounted on the pen-shaped housing through the pressing plate and is made slidable in the first through hole and the second through hole.

5. The test pencil of claim 4 wherein the first through hole is formed in a front plate of the cap, the sliding rod is mounted inside the front plate of the cap through the pressing plate, and an outer end of the sliding rod extends outward beyond the front plate of the cap, the test pencil further comprises a cap for covering the cap, the cap is used for pressing the outer end of the sliding rod when covering the front end of the cap, so that an inner end of the sliding rod moves towards the tact switch to press the tact switch, the tact switch is pressed and then turned on, and the test pencil is switched to a non-contact voltage measuring mode, when the cap is removed from the cap, an acting force on the outer end of the sliding rod is removed, and the tact switch is returned to an off state under a self-elastic force and then switched to a contact voltage measuring mode.

6. The test pencil of claim 5 wherein the middle of the slide rod is formed with a protruding ring, the protruding ring is clamped between the front end plate of the cap and the pressing plate to limit the sliding stroke of the slide rod.

7. The test pencil of claim 5 wherein said sensing unit comprises a screwdriver base and a screwdriver rod, said screwdriver base being mounted on said cap, said screwdriver rod being mounted on said screwdriver base and extending outwardly from said cap, said pencil cap being further adapted to cover said screwdriver rod within said pencil cap when said pencil cap is covered over said cap, said screwdriver base and screwdriver rod being adapted to be in conductive communication with said sensing signal input point.

8. The test pencil of claim 7, wherein the sensing unit further comprises a flat sensing piece, the outer end of the pencil cap is provided with a flat receiving portion, the sensing piece is arranged in the receiving portion of the pencil cap, the sensing piece is used for being in conductive connection with the screwdriver rod when the pencil cap covers the cap, the sensing piece is connected with a compression spring, and the compression spring is used for electrically connecting the sensing piece with the screwdriver rod when the pencil cap covers the cap.

9. The test pencil of claim 7 wherein the screwdriver rod is detachably mounted on the screwdriver base, the screwdriver rod is formed with a screwdriver bit at one end or both ends, or the screwdriver rod is non-detachably fixed on the screwdriver base.

10. The test pencil of claim 9 wherein the head shape of the screwdriver bit is a straight, cross, m, star, square, hex or Y shape.

11. The test pencil of claim 7 wherein the circuit board is provided with a contact piece for contacting the sensing signal input point, and a contact spring is provided on a side of the contact piece facing the screwdriver seat, the contact spring being adapted to be electrically connected to the screwdriver seat of the sensing unit.

12. The test pencil of claim 11 wherein a blind hole is formed on a side of the screwdriver seat facing the contact spring, a magnetic block is disposed in the blind hole, and the contact spring is electrically connected to the screwdriver seat through the magnetic block.

13. The test pencil of claim 1, wherein the circuit board further comprises a key module, the key module comprises a power key and a sensitivity key, the power key is used for controlling the test pencil to be turned on and off, and the sensitivity key is used for switching the sensitivity range of the test pencil.

14. The test pencil of claim 13, wherein a lighting lamp module is further disposed on the circuit board, the lighting lamp module includes a lighting lamp for lighting, the lighting lamp extends into the cap head, a light-emitting window is disposed at a front end of the cap head corresponding to the lighting lamp, and the sensitivity key SKEY is further configured to turn on and off the lighting lamp.

15. The test pencil of claim 13 wherein the circuit board further includes a function indicator light module, the function indicator light module including a power indicator light for indicating power on, the power indicator light for illuminating when the power is on.

16. The test pencil of claim 1 wherein the display unit displays the voltage intensity indicator using an L CD display screen, a nixie tube or a L ED light.

17. The test pencil of claim 1 or 16, wherein the voltage intensity marks are analog bars, and the display unit displays a number of analog bars corresponding to the magnitude of the acquired voltage to be detected according to the first control signal; or the voltage intensity is identified as a voltage value.

18. The test pencil of claim 1 or 16 wherein the display unit lights L the number of ED lights and/or lights L ED lights of different colors to represent the voltage intensity indication according to the first control signal.

19. The test pencil of claim 1 wherein the display unit comprises an L CD display screen, and a bi-color backlight module is further disposed on the circuit board, wherein the bi-color backlight module comprises two light emitting diodes emitting different colors, respectively, for illuminating the L CD display screen with two different colors of backlight.

20. The test pencil of claim 19 wherein the display unit is adapted to display corresponding text and/or symbols in the non-contact voltage measurement mode, to display corresponding text and/or symbols in the contact voltage measurement mode, and/or to display an under-voltage battery symbol in the under-voltage battery mode.

21. The test pencil of claim 19, wherein a buzzer alarm module is further disposed on the circuit board, the buzzer alarm module comprises a buzzer, the microcontroller is further configured to control the buzzer to emit a frequency sound corresponding to the acquired voltage to be detected according to the magnitude of the acquired voltage to be detected, the buzzer alarm module further comprises a signal lamp, and the microcontroller is further configured to control the signal lamp to illuminate a brightness corresponding to the acquired voltage to be detected, or control the signal lamp to emit a flashing frequency corresponding to the acquired voltage to be detected.

22. The test pencil of claim 13 wherein the sensitivity range of the non-contact voltage measurement mode includes a high sensitivity range of 12V to 1000V and a low sensitivity range of 48V to 1000V.

23. The test pencil of claim 21, wherein the sensitivity range of the non-contact voltage measuring mode includes a high sensitivity range of 12V to 1000V and a low sensitivity range of 48V to 1000V, and when measuring under the high sensitivity range of 12V to 1000V, the high sensitivity range of 12V to 1000V is divided into a plurality of sections, different color backlights of L CD display screen are lighted by a bi-color backlight module, different levels of prompting sound are sounded by a buzzer BUZ, and/or different numbers of analog bars are displayed by a L CD display screen to represent the voltage section where the detected voltage is located;

when the low-sensitivity measuring range of 48V-1000V is measured, the low-sensitivity measuring range of 48V-1000V is divided into a plurality of sections, different colors of backlight of an L CD display screen are lightened through a two-color backlight module, different levels of prompting sound is emitted through a buzzer BUZ, and/or different numbers of simulation bars are displayed through a L CD display screen to represent the voltage section where the detection voltage is located.

24. The test pencil of claim 19, wherein when the contact voltage measuring mode is used for measurement, the voltage detection range is 12-250V, the voltage detection range is divided into a plurality of sections, and different color backlights of L CD display screen are lighted by a two-color backlight module and/or different values are displayed by a L CD display screen to represent the voltage section of the detected voltage.

25. The test pencil according to claim 1, wherein a lighting lamp module is further disposed on the circuit board, the lighting lamp module comprises a lighting lamp for lighting, the lighting lamp extends into the cap head, and a light-emitting window is disposed at a front end of the cap head corresponding to the lighting lamp.

26. The test pencil of claim 2 wherein the switch is a toggle switch, and the voltage measuring mode switching unit comprises a toggle button provided on the pencil body, and the toggle switch is operated by the toggle button to switch between the non-contact voltage measuring mode and the contact voltage measuring mode.

27. The test pencil according to any one of claims 1 to 8, wherein the circuit board further has a phase sequence signal acquisition module and a key module, and the key module comprises a function switch FUNC for switching between a non-contact voltage measurement mode and a non-contact phase sequence measurement mode.

28. The test pencil according to any one of claims 1 to 8, wherein a function indicator light module is further provided on the circuit board, the function indicator light module includes a phase sequence indicator light indicating a non-contact phase sequence measurement mode, and the phase sequence indicator light is turned on when switching to the non-contact phase sequence measurement mode.

29. The test pencil of claim 27, wherein the phase sequence signal acquisition module is configured to acquire the phase sequence of the three-phase line to be detected in a non-contact manner via the sensing unit in a non-contact phase sequence measurement mode, and output the acquired signal to the microcontroller;

30. The test pencil of claim 29 wherein the display unit is further adapted to display corresponding text and/or symbols in the non-contact phase sequence measurement mode; and/or

31. The test pencil of claim 29, wherein the display unit comprises an L CD display screen, and the circuit board further comprises a bi-color backlight module, wherein the bi-color backlight module comprises two light emitting diodes emitting different colors, and the bi-color backlight module is configured to illuminate the different color backlights of the L CD display screen when the phase sequence measurement result is displayed to represent the positive phase sequence and the negative phase sequence, respectively.